Les has $3$ bills in her wallet. They are each worth $20$ dollars. How many dollars does Les have?
Solution: ${20}$ dollars is the same as ${2\text{ groups of ten}}$ dollars. There are $3$ bills. Total number of dollars: $\begin{aligned}&\phantom{=}3\times{2\text{ groups of ten}}\\\\ &= C{ 6\text{ groups of ten}}\\\\ &= C{60}\end{aligned}$ Les has $C{60}$ dollars.